In order to increase mobility of wireless communication devices, designers are challenged to figure out how to reduce sizes and weights of the wireless communication devices and also provide as many functions as possible. Powerful processors embedded in the wireless communication devices are able to provide various functions and great user experiences. However, it causes heavy power consumption while these processors are operating at full speed.
Because the wireless communication devices are designed in a compact size. A battery capacity on the wireless communication device (e.g., smart phones, tablets, or similar handheld devices) is limited. Also, it is difficult to dissipate heat generated by the operating processors. On the wireless communication devices, it is a critical issue for the designer to balance between the power consumption and the performance.